How do I use a library with my Android project using Gradle?

Question

I'm only just starting with Android development so I'm sure this is incredibly basic and a dumb question, but I'm getting the following error when I try and include a library to use in my code with Gradle:

Gradle 'MyApp' project refresh failed: You are using an old, unsupported version of Gradle. Please use version 1.6 or greater.

The library I'm trying to use is ION. All I've tried so far is adding the following lines into the build.gradle file.

dependencies {
    compile 'com.koushikdutta.ion:ion:1.1.5'
}

Which I guessed at based on this section of Koush's GitHub account, but what else do I need to do? Still download the jar and put it somewhere? I have looked at other questions/searched for guides on the basics of Gradle, but bizarrely I can't find a solid, definitive answer.

And how do I upgrade Gradle? Can it be done from within Android studio? I'm using Android Studio 0.2.13 on Windows 7 64bit:

SOLUTION: - Make sure you're putting the dependencies in the correct build.gradle file! Doh! It should be in the one just above your src folder, not the root!

Answer 1

Make sure that your buildscript contains the classpath with "gradle:0.5.+". Afterwards, navigate to the root directory of your project (one directory level above the build.gradle file) and (in the command line) run "./gradlew clean"

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.5.+'
    }
}
apply plugin: 'android'

repositories {
    mavenCentral()
}

android {
    compileSdkVersion 18
    buildToolsVersion "17.0.0"

    defaultConfig {
        minSdkVersion 9
        targetSdkVersion 18
    }

    sourceSets {
        main {
            manifest.srcFile 'MyApp\src\main\AndroidManifest.xml'
        }
    }
}

dependencies {
    compile "com.koushikdutta.ion:ion:1.1.5"
}